In the present study, children's early ability to organise words into sentences was investigated using the Weird Word Order procedure with Spanish-speaking children. Spanish is a language that allows for more flexibility in the positions of subjects and objects, with respect to verbs, than other previously studied languages (English, French, and Japanese). As in prior studies (Abbot-Smith et al., 2001; Chang et al., 2009; Franck et al., 2011; Matthews et al., 2005, 2007), we manipulated the relative frequency of verbs in training sessions with two age groups (three- and four-year-old children). Results supported earlier findings with regard to frequency: children produced atypical word orders significantly more often with infrequent verbs than with frequent verbs. The findings from the present study support probabilistic learning models which allow higher levels of flexibility and, in turn, oppose hypotheses that defend early access to advanced grammatical knowledge.

Children learn high phonological neighbourhood density words more easily than low phonological neighbourhood density words (Storkel, 2004). However, the strength of this effect relative to alternative predictors of word acquisition is unclear. We addressed this issue using communicative inventory data from 300 British English-speaking children aged 12 to 25 months. Using Bayesian regression, we modelled word understanding and production as a function of: (i) phonological neighbourhood density, (ii) frequency, (iii) length, (iv) babiness, (v) concreteness, (vi) valence, (vii) arousal, and (viii) dominance. Phonological neighbourhood density predicted word production but not word comprehension, and this effect was stronger in younger children.